Rotary fluid pressure device



Sept. 6, 1966 L. CHARLSON ROTARY FLUlD IRLISSUING DEVICE 2 Sheets--Sheet 1 Filed Nov. 18, 1964 INVENIUR. lymv L. Ckmflsmr p 1966 L. 1.. CHARLSON 3,270,681

ROTARY FLUID PRESSURE DEVICE Filed Nov. 18, 1964 2 Sheets-Sheet 1N VENTOR. LYNN L 0mm. scw

ATTORNEY United States Patent 3,270,681 ROTARY FLUID PRESSURE DEVICE Lynn L. Charlson, Minneapolis, Minn assignor to Germane Corporation, Minneapolis, Minn., a corporation of Minnesota Filed Nov. 18, 1964, Ser. No. 412,100

14 Claims. (Cl. l03130) This invention relates to rotary fluid pressure motors and pumps of the kind which utilize the type of gear 1 mechanism disclosed in United States Patent No. 1,682,563, issued August 28, 1928, to Myron P. Hill.

The mechanism disclosed in the Hill patent is referred to in the art as a gerotor and consists of an internally toothed ring member and an externally toothed star member Which partakes of a hypocycloidal movement and travels in an orbit about the axis of the ring member.

An object of the present invention is to provide a rotary fluid pressure motor or pump of the gerotor type having a new and improved valving and drive system.

Other objects and advantages will become apparent from the following specification, appended claims and attached drawings.

In the drawings:

FIG. 1 is a longitudinal sectional view of a rotary fluid pump or motor embodying the invention and taken on line I--I of FIG. 4;

FIG. 2 is an end view from the left side of FIG. 1;

FIG. 3 is an end view from the right side of FIG. 1;

FIG. 4 is a transverse sectional view taken on line IVIV of FIG. 1;

FIG. 5 is a transverse sectional view taken on line VV of FIG. 1; and

FIG. 6 is a fragmentary longitudinal sectional view taken on line VIVI of FIG. 5.

In the illustrated embodiment of the invention there is provided a sectional casing comprising a generally cylindrically shaped shaft section 10, a cylindrically shaped gerotor section 12 and a cylindrically shaped valving section 14. These casing sections are held together in axial alignment by a plurality of circumferentially spaced bolts 16.

Gerotor section 12 is a generally annularly shaped ring member which has a plurality of internal teeth 18. An externally toothed star member 20, having at least one fewer teeth 22 than ring member 12, is disposed eccentrically in the chamber or space formed and surrounded by ring member 12. Star member is moveable orbitally relative to the ring member 12, the axis 24 of star member 20 being moveable in an orbital path about the axis 26 of ring member 12. During orbital movement of star member 20 the teeth 22 thereof intermesh with the ring member teeth 18 in sealing engagement to form expanding and contracting cells 28 which are equal in number to the number of star member teeth 22.

With reference to FIG. 4, the vertical centerline 30 incidentally represents the line of eccentricity for the star member 20 for that particular position of the star member relative to the ring member 12. During orbital movement of the star member 20, and assuming the orbital movement is clockwise, the cells 28 on the left side of the line of eccentricity would be expanding and the cells 28 on the right side would be contracting. If the device is used as a motor, fluid under pressure is directed to the expanding cells and exhausted from the contracting cells. If the device is used as a pump, fluid is sucked into the expanding cells and delivered under pressure from the contracting cells. The valving arrangement which facilitates the pumping or motor action will be described further on herein.

With reference to FIG. 1, the shaft section 10 of the "ice casing for the device has a cylindrically shaped counterbore 32 which is concentric relative to the centerline 26 which is also the centerline for ring member 12. A eylindrically shaped shaft 34 having a stepped portion 36 of smaller diameter is rotatably disposed in the counterbore 32. An annularly shaped plate 37 is provided which is attachable to shaft casing section 10 with a plurality of circumferentially arranged bolts 36 for retaining shaft 34 in its installed position. The stepped portion 36 of the 9 shaft 34 may be driven by an electric motor or the like when the device is utilized as a pump or may drive apparatus such as a boat propeller when the device is utilized as a motor.

Shaft 34 and shaft casing section 10 are provided respectively with bores 40 and 42 which are in axial alignment by reason of both bores being concentric relative to the device centerline 26. The inner side of easing section 10 is in abutting engagement with ring member 12 and forms a side for the gerotor chamber. The bore 42 of the casing section 10 must thus be limited in diameter so that cells 28 formed between the teeth of the gerotor star and ring members will be closed by easing section 10 for all orbital positions of the star member 20.

Star member 20 has a bore 46 which is concentric relative to the teeth 22 thereof and the centerline 24 when the star member is in the position shown in FIGS. 1 and 4. The left side of the star bore 46 has a plurality of circumferentially arranged, axially extending teeth or splines 48 and the left side of the shaft bore 40 also has a plurality of circumferentially arranged, axially extending teeth or splines 50.

An intermediate shaft 52 is disposed in bores 40, 42 and 46 between shaft 34 and star member 20. The left and right ends of shaft 52 have splines 55 and 56 respectively which in each case are circumferentially arranged and extend axially. Splines 55 of shaft 52 are equal in number and mesh with splines 50 of shaft 34 and the same is true at the opposite end of intermediate shaft 52 wherein splines 56 of shaft 52 are equal in number and mesh with splines 48 of star 20.

Star member 20 is eccentrically disposed relative to ring member 12, as mentioned above, and intermediate shaft 52 is thus always in cocked or tilted position relative to shaft 3-2, which has the same axis as ring member 12, and the axis of star member 20. In operation a star member having six teeth will make one revolution about its own axis for every six times the star member orbits in the opposite direction about the axis 26 of the ring member 12. Thus, the right end of intermediate shaft 52 has both orbital and rotational movement in common with the star member 20 while the left end of shaft 52 has only rotational movement in common with shaft 34. The spline connections between intermediate shaft 52 and shaft 3 4 and between intermediate shaft 52 and star member 20 are forms of universal joints which permit shaft 52 to have the motion described above. When the device is utilized as a pump, star member 20 will be gyrated by a turning force applied to shaft 34 and transmitted to star member 20 through intermediate shaft 52. When the device is used as a motor, the force created by the rotation of star member 20 about its own axis 24 will be transmitted through intermediate shaft 52 to shaft 34 to cause turning of shaft 34.

The casing valve section 14 has a counterbore 58 which is concentric relative to the axis or centerline 26 and has cylindrically shaped valve 60 rotatably disposed therein. The diameter of valve 60 is at least as large as the diameter of the gerotor chamber formed by the ring member 12 so that the cells 28 formed between the teeth of the gerotor star and ring members will be closed by the radial face 66 of valve 60 for all orbital positions of star member 20.

Valve 60 is provided with an eccentrically disposed counterbore 62 which for convenience may have the same diameter as star member bore 46. Counterbore 62 is offset from the axis of rotation 26 of the valve 60 a distance equal to the distance that star member 20 is eccentrically offset relative to ring member 12. Valve 60 is connected to star member 20 by aligning valve counterbore 62 with star member bore 46 and inserting a short shaft 64 in the bore formed by the two bores 46 and 62. Short shaft 64 is rotatably mounted relative to star member 20 and valve 60 and the orbiting of star member 20 will cause valve 60 to rotate in the same direction and at the same speed as the orbiting speed of the star member 20 and vice versa.

With reference to FIGS. 4, 5 and 6, the face 66 of valve 60 adjacent star member is provided with two lobe or crescent shaped recesses 70 and 72 symmetrically arranged on diametrically opposite sides of valve. 60. Valve casing member 14 has two radially extending ports 74 and 76 each of which connect the periphery or outer surface of valve casing 14 with the bore 58. Each of the ports 74 and 76 may be an inlet or outlet port depending upon the direction of the rotation of the shaft 34. Port 74 is fluidly connected to recess 70 and port 76 is fluidly connected to recess 72. Assuming the device is functioning as a motor and that fluid under pressure is introduced through port 74, the pressurized fluid will flo w to recess 70 and into two cells 28 on the left side of the line of eccentricity 30 (FIG. 4) and the expansion of these two cells will cause star member 20 to move in an orbital clockwise path. Simultaneously the cells 28 on the right side of the line of eccentricity will contract and the fluid therein will flow into recess 72 and out of the device through port 76. The orbiting of star member 20 causes valve to be rotated through eccentric shaft 64 and valve 60 will rotate at the same speed that star member 20 orbits and in the same direction. Recesses and 72 in valve 60 will thus always rotate in unison with the orbiting of star member 20 and will always be on opposite sides of the line of eccentricity of the star member 20.

The fluid connections between ports 74 and 76 and valve recesses 70 and 72 are formed partly in the valve casing 14 and partly in the valve 60. Two axially spaced annular grooves 78 and 80 are formed in valve casing 14 which are aligned with and communicate with the ports 74 and 76. Two other axially spaced annular grooves 82 and 84 are formed on valve 60 which are axially aligned respectively with the casing grooves 78 and 80 to form two enclosed annular passages. Channels 86 and 88 are provided in valve 60 which respectively connect groove 82 and port 76 to the valve recess 70 and groove 84 and port 76 to valve recess 72.

From the foregoing it will be understood that the rotary fluid pressure device may be utilized as either a pump by connecting one of the ports 74 or 76 to a source of fluid and rotating the shaft 34 in the correct direction or as a motor by connecting one of the ports 74 or 76 to a source of fluid pressure and connecting shaft 34 to a mechanical device desired to be driven. When used as a pump a relatively slow speed imparted to shaft 34 will cause relatively rapid orbiting of star member 20 and result in a high fluid delivery rate. When used as a motor the shaft 34 makes one rotation for every six orbiting cycles of the star member 20, in a case where star member has six teeth, and as a result the shaft 34 produces a relatively high torque at a relatively slow speed.

While one embodiment of the invention is described here, it will be understood that it is capable of modification, and that such modification, including a reversal of ports, may be made without departure from the spirit and scope of the invention as defined in the claims.

What I claim is:

1. In a fluid pressure device, fluid inlet and outlet means, an internally toothed ring member defining the outer wall of a chamber, a cooperating externally toothed star member disposed eccentrically in said chamber, one of said members being capable of orbital movement about the axis of the other of said members with the teeth of said members intermeshing in sealing engagement to form expanding cells on one side of the line of eccentricity and contracting cells on the other side of said line during relative movement between said members, one of said members being rotatable about its own axis relative to said other member at a slower speed than said orbital movement during relative rotation between said members, valve means operatively connected to the orbiting one of said members so that its rotational speed is the same as the orbiting speed of said one of said members, said valve means defining fluid passage means which com prise fluid supply means only on one side thereof in communication with said fluid inlet means and fluid exhausting means only on the other side thereof in communication with said fluid outlet means, said valve means being indexed with reference to the position of said star member relative to said ring member so that upon rotation of said valve means said fluid supply means communicate with said expanding cells, a drive shaft rotatably mounted relative to one of said members, and intermediate shaft means having one end thereof operatively secured to one of said members for common orbital and rotary movement therewith and the other end operatively connected to said drive shaft for common rotary movement with said drive shaft.

2. A fluid pressure device as defined in claim 1 in which said ring member is stationary.

3. A fluid pressure device as defined in claim 1 having a body portion attached to said ring member for receiving said fluid inlet and outlet means.

4. A fluid pressure device as defined in claim 1 in which said star member has fewer teeth than said ring member.

5. A fluid pressure device as defined in claim 4 in which said star member has one less tooth than said ring member.

6. A fluid pressure device as defined in claim 3 in which said body portion defines a bore having a first annular groove communicating with said inlet means and a second annular groove axially spaced from said first annular groove communicating with said outlet means, said valve means being rotatably disposed in said bore with said fluid supply and exhaust means thereof being in respective communication with said annular grooves, said fluid supply and exhaust means being formed on diametrically opposite sides of said valve means in the form of crescent shaped recesses.

7. A fluid pressure device as defined in claim 1 in which the connection between said intermediate shaft and said one of said members is a universal joint comprising groove and abutment means and the connection between said intermediate shaft and said drive shaft is a universal joint comprising groove and abutment means.

8. In a fluid pressure device, fluid inlet and outlet means, an internally toothed ring member defining the outer wall of a chamber, a cooperating externally toothed star member disposed eccentrically in said chamber and being capable of orbital movement about the axis of said ring member, the teeth of said members intermeshing in sealing engagement to form expanding cells on one side of the line of eccentricity and contracting cells on the other side of said line during relative movement between said members, said star member being rotatable about its own axis in the opposite direction and at a slower rate of speed than said orbital movement during relative rotation between said members, valve means operatively coupled to said star member so that the rotational speed of said valve means is the same as the orbiting speed of said star member, said valve means defining fluid passages which comprise fluid supply means only one one side thereof in communication with said fluid inlet means and fluid exhausting means only on the other side thereof in communication with said fluid outlet means, said valve means being indexed with reference to the position of said star member relative to said ring member so that upon rotation of said valve means said fluid supply means establish communication with said expanding cells and said fluid exhausting means establish communication with said collapsing cells, a drive shaft rotatably mounted relative to said ring member, and intermediate shaft means having one end thereof operatively secured to said star member for common orbital and rotary movement with said star member and the other end operatively connected to said drive shaft for common rotary movement with said drive shaft.

9. A fluid pressure device as defined in claim 8 in which said ring member is stationary.

10. A fluid pressure device as defined in claim 8 having a body portion attached to said ring member for receiving said fluid inlet and outlet means.

11. A fluid pressure device as defined in claim 8 in which said star member has fewer teeth than said ring member.

12. A fluid pressure device as defined in claim 8 in which said star member has one less tooth than said ring member.

13. A fluid pressure device as defined in claim 10 in which said body portion defines a bore having a first annular groove communicating with said inlet means and a second annular groove axially spaced from said first annular groove communicating with said outlet means, said valve means being rotatably disposed in said bore with said fluid supply and exhaust means thereof being in respective communication with said annular grooves, said fluid supply and exhaust means being formed on diametrically opposite sides of said valve means in the form of crescent shaped recesses.

14. A fluid pressure device as defined in claim 8 in which the connection between said intermediate shaft and said star member is a universal joint comprising groove and abutment means and the connection between said intermediate shaft and said drive shaft is a universal joint comprising groove and abutment means.

References Cited by the Examiner UNITED STATES PATENTS Re. 25,126 2/1962 Charlson 91-56 Re. 25,291 12/1962 Charlson 9156 1,682,563 8/1928 Hill 23014l 2,132,812. 10/1938 Wahlmark 103-126 2,758,573 8/1956 Krozal 91-56 3,087,436 4/1963 Dettlof et a1 l03130 MARK NEWMAN, Primary Examiner.

W. J. GOOD-LIN, Assistant Examiner. 

1. IN A FLUID PRESSURE DEVICE, FLUID INLET AND OUTLET MEANS, AN INTERNALLY TOOTHED RING MEMBER DEFINING THE OUTER WALL OF A CHAMBER, A COOPERATING EXTERNALLY TOOTHED STAR MEMBER DISPOSED ECCENTRICALLY IN SAID CHAMBER, ONE OF SAID MEMBERS BEING CAPABLE OF ORBITAL MOVEMENT ABOUT THE AXIS OF THE OTHER OF SAID MEMBERS WITH THE TEETH OF SAID MEMBERS INTERMESHING IN SEALING ENGAGEMENT TO FORM EXPANDING CELLS ON ONE SIDE OF THE LINE OF ECCENTRICITY AND CONTRACTING CELLS ON THE OTHER SIDE OF SAID LINE DURING RELATIVE MOVEMENT BETWEEN SAID MEMBERS, ONE OF SAID MEMBERS BEING ROTATABLE ABOUT ITS OWN AXIS RELATIVE TO SAID OTHER MEMBER AT A SLOWER SPEED THAN SAID ORBITAL MOVEMENT DURING RELATIVE ROTATION BETWEEN SAID MEMBERS, VALVE MEANS OPERATIVELY CONNECTED TO THE ORBITING ONE OF SAID MEMBERS SO THAT ITS ROTATIONAL SPEED IS THE SAME AS THE ORBITING SPEED OF SAID ONE OF SAID MEMBERS, SAID VALVE MEANS DEFINING FLUID PASSAGE MEANS WHICH COM- 